/*
* mount()
*
* XXX
*
* XXX make sure no required ops are NULL
* XXX make sure no optional ops you are using are NULL
* XXX unmount should be required.
*
* COPYRIGHT (c) 1989-2010.
* On-Line Applications Research Corporation (OAR).
*
* Copyright (c) 2010 embedded brains GmbH.
*
* The license and distribution terms for this file may be
* found in the file LICENSE in this distribution or at
* http://www.rtems.com/license/LICENSE.
*
* $Id$
*/
#if HAVE_CONFIG_H
#include "config.h"
#endif
#include <sys/types.h>
#include <sys/stat.h>
#include <rtems/chain.h>
#include <rtems/seterr.h>
#include <fcntl.h>
#include <unistd.h>
#include <errno.h>
#include <stdlib.h>
#include <string.h>
#include <rtems/libio_.h>
static RTEMS_CHAIN_DEFINE_EMPTY(mount_chain);
/*
* Default pathconfs.
*/
const rtems_filesystem_limits_and_options_t rtems_filesystem_default_pathconf = {
5, /* link_max: count */
128, /* max_canon: max formatted input line size */
7, /* max_input: max input line size */
255, /* name_max: max name */
255, /* path_max: max path */
1024, /* pipe_buf: pipe buffer size */
0, /* posix_async_io: async IO supported on fs, 0=no, 1=yes */
0 , /* posix_chown_restrictions: can chown: 0=no, 1=yes */
1, /* posix_no_trunc: error on filenames > max name, 0=no, 1=yes */
0, /* posix_prio_io: priority IO, 0=no, 1=yes */
0, /* posix_sync_io: file can be sync'ed, 0=no, 1=yes */
0 /* posix_vdisable: special char processing, 0=no, 1=yes */
};
static bool is_node_fs_root(
const rtems_filesystem_mount_table_entry_t *mt_entry,
void *arg
)
{
return arg == mt_entry->mt_fs_root.node_access;
}
static rtems_filesystem_mount_table_entry_t *alloc_mount_table_entry(
const char *source_or_null,
const char *target_or_null,
const char *filesystemtype,
size_t *target_length_ptr
)
{
const char *target = target_or_null != NULL ? target_or_null : "/";
size_t filesystemtype_size = strlen( filesystemtype ) + 1;
size_t source_size = source_or_null != NULL ?
strlen( source_or_null ) + 1 : 0;
size_t target_size = strlen( target ) + 1;
size_t size = sizeof( rtems_filesystem_mount_table_entry_t )
+ filesystemtype_size + source_size + target_size;
rtems_filesystem_mount_table_entry_t *mt_entry = calloc( 1, size );
if ( mt_entry != NULL ) {
char *str = (char *) mt_entry + sizeof( *mt_entry );
memcpy( str, filesystemtype, filesystemtype_size );
mt_entry->type = str;
str += filesystemtype_size;
memcpy( str, source_or_null, source_size );
mt_entry->dev = str;
str += source_size;
memcpy( str, target, target_size );
mt_entry->target = str;
}
*target_length_ptr = target_size - 1;
return mt_entry;
}
/*
* mount
*
* This routine will attempt to mount a new file system at the specified
* mount point. A series of tests will be run to determine if any of the
* following reasons exist to prevent the mount operation:
*
* 1) The file system type or options are not valid
* 2) No new file system root node is specified
* 3) The selected file system has already been mounted
* 4) The mount point exists with the proper permissions to allow mounting
* 5) The selected mount point already has a file system mounted to it
*
*/
int mount(
const char *source,
const char *target,
const char *filesystemtype,
rtems_filesystem_options_t options,
const void *data
)
{
rtems_filesystem_fsmount_me_t mount_h = NULL;
rtems_filesystem_location_info_t loc;
rtems_filesystem_mount_table_entry_t *mt_entry = NULL;
rtems_filesystem_location_info_t *loc_to_free = NULL;
bool has_target = target != NULL;
size_t target_length = 0;
/*
* Are the file system options valid?
*/
if ( options != RTEMS_FILESYSTEM_READ_ONLY &&
options != RTEMS_FILESYSTEM_READ_WRITE )
rtems_set_errno_and_return_minus_one( EINVAL );
/*
* Get mount handler
*/
mount_h = rtems_filesystem_get_mount_handler( filesystemtype );
if ( !mount_h )
rtems_set_errno_and_return_minus_one( EINVAL );
/*
* Allocate a mount table entry
*/
mt_entry = alloc_mount_table_entry(
source,
target,
filesystemtype,
&target_length
);
if ( !mt_entry )
rtems_set_errno_and_return_minus_one( ENOMEM );
mt_entry->mt_fs_root.mt_entry = mt_entry;
mt_entry->options = options;
mt_entry->pathconf_limits_and_options = rtems_filesystem_default_pathconf;
/*
* The mount_point should be a directory with read/write/execute
* permissions in the existing tree.
*/
if ( has_target ) {
if ( rtems_filesystem_evaluate_path(
target, target_length, RTEMS_LIBIO_PERMS_RWX, &loc, true ) == -1 )
goto cleanup_and_bail;
loc_to_free = &loc;
/*
* Test to see if it is a directory
*/
if ( loc.ops->node_type_h( &loc ) != RTEMS_FILESYSTEM_DIRECTORY ) {
errno = ENOTDIR;
goto cleanup_and_bail;
}
/*
* You can only mount one file system onto a single mount point.
*/
if ( rtems_filesystem_mount_iterate( is_node_fs_root, loc.node_access ) ) {
errno = EBUSY;
goto cleanup_and_bail;
}
/*
* This must be a good mount point, so move the location information
* into the allocated mount entry. Note: the information that
* may have been allocated in loc should not be sent to freenode
* until the system is unmounted. It may be needed to correctly
* traverse the tree.
*/
mt_entry->mt_point_node.node_access = loc.node_access;
mt_entry->mt_point_node.handlers = loc.handlers;
mt_entry->mt_point_node.ops = loc.ops;
mt_entry->mt_point_node.mt_entry = loc.mt_entry;
/*
* This link to the parent is only done when we are dealing with system
* below the base file system
*/
if ( loc.ops->mount_h( mt_entry ) ) {
goto cleanup_and_bail;
}
} else {
/*
* Do we already have a base file system ?
*/
if ( !rtems_chain_is_empty( &mount_chain ) ) {
errno = EINVAL;
goto cleanup_and_bail;
}
/*
* This is a mount of the base file system --> The
* mt_point_node.node_access will be left to null to indicate that this
* is the root of the entire file system.
*/
}
if ( (*mount_h)( mt_entry, data ) ) {
/*
* Try to undo the mount operation
*/
loc.ops->unmount_h( mt_entry );
goto cleanup_and_bail;
}
/*
* Add the mount table entry to the mount table chain
*/
rtems_libio_lock();
rtems_chain_append( &mount_chain, &mt_entry->Node );
rtems_libio_unlock();
if ( !has_target )
rtems_filesystem_root = mt_entry->mt_fs_root;
return 0;
cleanup_and_bail:
free( mt_entry );
if ( loc_to_free )
rtems_filesystem_freenode( loc_to_free );
return -1;
}
bool rtems_filesystem_mount_iterate(
rtems_per_filesystem_mount_routine routine,
void *routine_arg
)
{
rtems_chain_node *node = NULL;
bool stop = false;
rtems_libio_lock();
for (
node = rtems_chain_first( &mount_chain );
!rtems_chain_is_tail( &mount_chain, node ) && !stop;
node = rtems_chain_next( node )
) {
const rtems_filesystem_mount_table_entry_t *mt_entry =
(rtems_filesystem_mount_table_entry_t *) node;
stop = (*routine)( mt_entry, routine_arg );
}
rtems_libio_unlock();
return stop;
}
